Cellulosic textile fabric



April 8, 1952 A. JOHNSON ET AL CELLULOSIC TEXTILE FABRIC Filed Jan. 8,1948 [019M ,4 60/1/1 05? VAfi/V 5) MAW/V6 AZAAZ/ 50101915 141 G/lV/Wf/IF/l W/r (07704 Ji l/[f MM.

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:25 viz INVENTORS. ARTHUR JOHNSON & JOHN BAMBER SPEAKMAN Patented Apr.8, 1952 CELLULOSIC TEXTILE FABRIC Arthur Johnson and John B-amberSpeakman, Leeds, England, assignors to Alginate Industries Limited,Maidenhead, England, a British com- Application January 8, 1948, SerialNo. 1,150 In Great Britain April 11, 1941 2 Claims.

This application is a continuation-in-part of our copending applicationSerial No. 571,758, filed January 8, 1945, now Patent No. 2,435,543,which in turn is a division of our application Serial No. 450,012, filedJuly 7, 1942, now abancloned.

This invention comprises improvements in or relating to cellulosictextile fabrics.

In the weaving of textile fabrics it is known to use yarns twisted withcotton threads, which latter are intended to remain in the fabric onlytemporarily, and after weaving to remove the cotton by treatment withsulphuric acid, drying and baking, whereby the cotton is carbonised andreduced to a powder, which is easily dusted out. Cotton and wool yarnsare twisted together in such a sense as to leave the wool yarn in thetwofold thread either twistless or deficient in twist so that when thecotton is removed in carbonising a soft and lustrous fabric is obtained.The

process is applicable only to wool fibres but even they are liable to bedamaged to some extent by the use of acid, so that the avoidance of theuse of acid is a matter of importance.

The present invention relates to the production of fabrics from yarns ofcellulosic staple fibres of such fineness as is not normally capable ofbeing made into fabric. In particular the invention comprises a wovencellulose staple fibre fabric comprising yarn of such fineness that itis incapable by itself of withstanding the strains imposed in weaving.The invention is not, however, limited to woven fabrics but includesknitted and lace fabrics.

It is found that soluble alginic fibres can be employed successfullywith all cellulosic fibres and not simply with the acid-resisting woolfibres which are sometimes used twisted up with cotton in processeswhich involve subsequent removal of. the cotton by acid. Soluble alginicfibres are known in themselves; for example fibres of alginic acid andmetal alginates like calcium alginate are known, both types beingsoluble in soap, soda and other alkaline solutions.

The invention further comprises a process for the manufacture of a wovenor knitted or lace fabric characterised by producing composite yarn bytwisting together soluble alginic fibres and cellulosic staple textilefibres of such fineness as is too weak to be handled by itself in makingthe fabric, employing such composite yarn, with or without other yarn,in making the fabric and thereafter dissolving the said soluble alginicfibres out of the fabric so as to set the fine cellulosic staple fibresfree.

Many alginic fibres, such for example as fibres of calcium alginate, aresoluble in an aqueous solution of soap or sodium carbonate or can beconverted to alginic acid by treating with an acid of such strength aswill not injure wool fibres, in which converted state they are solublein, say, sodium carbonate, and it is this readily soluble property ofmany alginic fibres which is utilised according to the present inventionand the expression soluble alginic fibres is to be understoodaccordingly.

The phrase fibres is used in this specification as including both longfilaments and relatively short fibres, and where short fibres arereferred to specifically they are referred to as staple fibres.

The lower limits of fineness with which yarns ofv staple cellulosicfibres can be spun, or woven, depend upon the nature of the fibres, andare herein specified in terms of yards per pound of yarn, in order toavoid any confusion between the difiering manners of reckoning thefineness of cotton or linen or viscose staple fibres, which are thethree commercially important kinds of such fibres. The finest linenyarns producible on a commercial scale have a length of about 90,000yards per pound weight. Such yarns are too weak to be woven in a powerloom, the finest linen yarns for weaving having a length of about 48,000yards per pound.

The finest cotton yarns which can be spun have a length of as much as336,000 yards per pound, but cotton of such fineness cannot normally bewoven in a power loom, the finest cotton for this purpose being about134,000 yards per pound.

The finest viscose staple fibre yarns which can be spun are 56,000 yardsper pound but such yarns cannot be woven normally in a power loom, thefinest yarn for the purpose being about 22,400 yards per pound.

According to one feature of this invention, linen yarn finer than 48,000yards per pound or cotton yarn finer than 134,000 yards per pound orviscose staple fibre yarn finer than 22,400 yards per pound is twistedwith soluble alginate yarn to produce a composite yarn capable of beingwoven on a power loom notwithstanding the fact that the yarn by itselfcould not be so woven and after weaving the alginate yarnis removed by aweak alkaline scour to leave a fabric finer than could otherwise beproduced.

,The cellulosicfibres in the composite yarn may, moreover, besubstantially untwisted, or less twisted than would be necessary towithstand trous or stronger fabric is produced. In explanation of thisit may be pointed out that certain fabrics are distinguished by theirsoft and fullhandling properties. Although these tactile qualities .mayoften be enhanced by suitable finishing .processes, they are largelydetermined by the structure of the yarns from which the fabrics aremade. Ordinary yarns must, of necessity, be twisted sufiiciently towithstand the strains imposed in weaving, but softness decreases as thetwist increases. Thus certain yarns when twisted sufficiently to besuitable for weaving may contain so much twist as to prevent the desireddegree of softness being realised in the finished fabric. In the casewhere, according to the present invention a yarn of cellulosic fibres istwisted to form a 'composite thread with soluble alginic yarn thealkaline wash removes the alginic fibres and if the composite yarn has.been twisted in such a manner a that, .in twisting, the original twistin "the cellulosic fibres is practically or wholly untwisted, thecellulosicfibres which remain after washing will -be twistless, or atall events less twisted than would be necessary for weaving or other-"wise-making into fabric by themselves and the resulting fabric will besofter. Moreover, such a process gives a fabric possessing a higherlustre than one composed of yarns-twistedso as to withstand weaving, andthe same principle can, of course, be-applied'to increase the.lustre ofindividual threads in afabric, such as coloured and uncolouredstripingthreads. It will be observed that the word yarn is employed in abroad senseras includinggroups of fibres or filaments which aretwistless, such as those left twistless in the finishedfabric,accordingto this. invention.

'The effectsaccording tothe present invention can be obtained withordinary .textilefibres of all kinds, including cotton, linen .andviscose staple, and not simply acid-resistant fibres such -as'wool andmohair. Animportant series of new types of .fabric is thus madeavailablefor the first time.

One important advantage of the manufacture of fabrics in accordance withthis invention from threads whichare twistless or little twisted afterremoval of the soluble alginic yarn is that a twistless or littletwisted .thread may be made to develop the maximum strength of thefibres in the woven fabric. Thus, for example, a fabric which .both warpand weft are woven from cotton in such a wayas to leave the fibrestwistless or little twisted in the finished fabric may for .a givenweight be as strong as or even stronger than .a fabric made .from cottonyarns having normal twist. The cotton threads 'couldnot be 'wovenby'themselves without being twisted,but

'by the use of the alginic'yarn for binding them together duringweaving, the weaving operation becomes possible with the twistless orlittletwisted cotton.

The preferred form in which the soluble alginic threads are employed inaccordance with this invention is in the form of calcium alginate which'is soluble in soap or soda solutions. When cal- -cium alginate is usedthe attack by the soap leads to the production of an insoluble metalsoap, for 'example'calcium oleate. In cases where the presence of thisinsoluble metal soap would be objectionabla'say in dyeing, otheralkaline scours can be substituted, for example,-fatty alcohol sulphateswithsoda or a mixture of soap, soda and one ofthe known-polymers ofalkali phosphates "which prevent precipitation of calcium soaps.

Again the alginic yarn may be converted to alginic acid by a mild acidtreatment followed by removal in sodium carbonate solution and this willensure that no calcium soaps remain in the fabric after treatment.

In the accompanying drawings which illustrate our inventiondiagrammatically.

Figure 1 is a diagram of one form of fibre with a twisted cellulosecomponent.

Figure 2 is a diagram of a second form with the cellulose componentuntwisted,

Figure 3 represents a fabric made by weaving the yarn shown in Figure 1into a fabric, and

Figure 4 is a fiow sheet illustrating the steps of our process.

To produce the yarn shown in Figure 1 the cellulose component, which maybe of linen, cotton or viscose staple fibre, and is indicated by thefibres Ii, is first spun into yarn by itself. Thereafter it is twistedtogether with yarn of calcium alginate, shown by the continuous filament[-2. It will'be noted that thishasbeen done so that thecellulosic'component remains twisted in the combined yarn and so if theyarn is woven or knitted or otherwise made into fabric, on removal ofthe calcium alginate in an alkaline bath the cellulosic-constituent willretain its twisted formation.

In Figure 2 the cellulosic constituent i3 is untwisted orsubstantiallyso and the continuous 'alginic constituent I4 is wound round it andkeeps it together. This is-effected by winding together the alginatefibre yarn-and the cellulosic yarn with a direction of twist opposite tothat initiallygiven to the cellulosic yarn when it is first spun,-sothat in twisting them together the initial twist-is taken-out of thecellulosic yarn.

The following examplesare illustrative ofmanufacture in accordance withthe invention:

Example I A fine linen yarn is spun of such fineness as to have a lengthof 90,000 yards perpound weight. This is twisted with a calcium alginatefilament of 100 denier which gives the combined yarn sufficient strengthto be woven on a power loom.

. The direction of twisting is such asto retain the twist of the linenyarn as shown in Figure 1. A

fabric is woven therefrom and after weavingthe calcium alginate fibresare dissolved out by means .of an alkaline scour comprising a weaksodium carbonate solution containing also a small percentage of soap andof "Calgon (sodium hexametaphosphate). The result is a linen fabricwhich is lighter than can be produced by usual commercial methods inpower looms.

Example II possible, by ordinary commercial methods, to

produce a woven fabric of such fineness as is here indicated.

Example III Viscose staple fibre is taken and spun into a. fine yarnhaving a length of 56,000 yards per pound. This represents a finer yarnthan can normally be woven; it is twisted with an alginate filamenthaving a fineness of 100 denier so as to retain the twist of the viscosestaple fibre, and woven, after which the alginate yarn is removed asdescribed in Example I and a stable-fibre viscose fabric results ofgreat lightness, such as could not heretofore be produced.

Example IV A composite yarn is produced consisting of one thread of /305cotton, which may be mercerised, twisted with a 100 denier calciumalginate rayon, so that the cotton thread is in a twistless form. Thiscomposite thread is used as a striping thread in a fabric, the alginaterayon enabling the twistless cotton to withstand the weaving strains.After weaving, the supporting thread of calcium alginate is removed bymeans of the normal alkaline scour which is used in finishing fabricsand leaves the /303 twistless cotton stripe. This cotton stripe will befound to have far greater covering power and to be much more prominentand lustrous than a stripe woven from an ordinary twisted mercerisedcotton. Such a twisted cotton consists normally of two threads of /scscotton twisted together with twentythree turns per inch and the twist inthe cotton detracts from its covering power and from its lustre. ascompared with the twistless /aoS in accordance with the presentinvention.

Example V A fabric is woven in which the warp and the weft both consistof /ao's cotton yarn twisted with a 100 denier calcium alginate rayon toform a composite thread in which the cotton portion is twistless. Afterweaving, the calcium alginate threads are removed by the alkaline scourleaving a fabric entirely consisting of 1/30S twistless cotton threads.Such threads press flat and, providing the residual threads are packedas tightly as possible, they afford the maximum possible strength to thefabric and owing to their flattened form they leave smaller aperturesbetween the threads in the finished fabric. Such a fabric is stronger,thinner and requires less dope to fill the apertures than an equivalentfabric woven from ordinary twisted cotton.

Example VI A composite yarn similar to that of Example IV of cotton andalginate fibres, the cotton fibres being untwisted as shown in Figure 2hereof, is taken, and woven into a compound fabric with other yarns sothat the composite yarn forms the centre portion of the fabric and isinterwoven with outer cloth portions of plain cotton fabric so that theuntwisted yarn constitutes a soft filling between the outer cloths whenthe soluble alginic fibres have been dissolved.

Example VII Composite cotton and alginate yarn such as is referred to inExamples IV to VI is taken and woven as wadding threads on the surfaceof a cotton fabric. After removal of the alginic yarn by scouring, asalready described, the result is a very soft layer on the face of thefabric. This may be produced either on one face or both faces of thefabric.

We claim:

1. A woven fabric substantially consisting of singles cotton yarn havinga fineness greater than 134,000 yards per pound, wound with alginateyarn of between 50 and denier, the alginate yarn being soluble in analkaline bath without injury to the cotton yarn.

2. A process of making woven fabrics which comprises winding alkalisoluble alginate yarn having a fineness of between 50 and 100 denierwith cotton staple yarn having a fineness greater than 134,000 yards perpound to form a composite yarn, weaving a fabric from the composite yarnand thereafter washing the fabric in an alkaline bath to dissolve thealginate yarn.

ARTHUR JOHNSON. JOHN BAMBER SPEAKMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 362,318 Scheppers May 3, 18871,021,712 Wilkinson Mar. 26, 1912 2,011,916 Simonds Aug. 20, 19352,159,265 Gash May 23, 1939 2,332,738 Meade Oct. 26, 1943 2,435,543Johnson Feb. 3, 1948 OTHER REFERENCES American Cotton Handbook, firstedition, Barnes Printing Co., New York, 1941, page 512. (Copy in Div.21.)

International Library of Technology, Yarns. Cloth Rooms, Mill Engrng,Reeling, Baling. Winding, International Textbook Co., Scranton, Pa. 1906(pages 16 and 17). (Copy in Div. 21.)

Bendure et al., Americans Fabrics, Macmillon Co., 1947, New York, page303. (Copy in Div.21.)

2. PROCESS OF MAKING WOVEN FABRICS WHICH COMPRISES WINDING ALKALISOLUBLE ALIGNATE YARN HAVING A FINENESS OF BETWEEN 50 AND 100 DENIERWITH COTTON STABLE YARN HAVING A FINENESS GREATER THAN 134,000 YARDS PERPOUND TO FORM A COMPOSITE YARN, WEAVING A FABRIC FROM THE COMPOSITE YARNAND THEREAFTER WASHING THE FABRIC IN AN ALKALINE BATH TO DISSOLVE THEALGINATE YARN.